Another Lycoming crankshaft ADAnother Lycoming crankshaft AD

September 29, 2006

Another Lycoming crankshaft AD

The FAA on Friday issued an airworthiness directive (AD) that would require the replacement of certain crankshafts in some 3,800 Lycoming 360- and 540-series reciprocating engines in popular Piper, Cessna, Mooney, and Beechcraft aircraft, among others. The AD, which becomes effective November 3, requires owners to replace the crankshaft at normal overhaul, when the crankcase is split for whatever reason, or within 12 years of the time the crankshaft was put into service.

Lycoming is offering replacement crankshafts at a reduced price ($2,000 instead of $16,000) for the next three years, or at no charge if the overhaul is done by the Lycoming factory within 12 years.

But in a previous Lycoming crankshaft AD, the company bore the entire cost of repairing the engines.

"AOPA is pressing for similar customer consideration, since the possible crankshaft defect is the same problem that the previous AD addressed in a different series of engines," said Luis Gutierrez, AOPA director of regulatory and certification policy.

AOPA had argued that the 12-year calendar limit was not related to safety and would be burdensome on some owners.

The FAA disagreed in its final rule. "While we stated in the proposal that the unsafe condition was unrelated to calendar time, a compliance end-time is necessary to minimize the probability of a crankshaft failure at operating times less than the specified overhaul interval," the agency said in reply. "The variability of the size and orientation of the metallurgical anomalies present in the identified crankshafts results in variation in the operating times at which failures could occur."